Skin care compositions contain a variety of additives that provide an array of benefits to the composition. Sunscreen compositions (including compositions that provide sunscreen protection benefits, such as certain cosmetics and creams), for instance, contain additives that offer protection from ultraviolet (“UV”) radiation, which can damage the skin. UV radiation can be classified as UVA (long wave; i.e., wavelengths of 320-400 nm) and UVB (short wave; i.e., wavelengths of 290 to 320 nm). The efficacy of a sunscreen formulation is measured by its sun protection factor (“SPF”). Since both UVA and UVB forms of radiation are harmful, sunscreen formulations preferably offer protection from both kinds of rays. Inorganic metal oxide particles, such as titanium dioxide and zinc oxide, provide absorption of UVA and UVB radiation and to this end are commonly incorporated into sunscreen formulations. Inorganic metal oxides, however, can cause negative aesthetic qualities such as poor sensorial feel and an undesirable white appearance, both of which may be due to agglomeration of particles and poor distribution on skin.
There is a need to develop new skin care compositions, such as sunscreen formulations, that contain sunscreen boosters which will help provide a high SPF, while improving aesthetic qualities of such formulations such as sensorial feel and visual appearance.